Trusting something is really there

Late last year Alister McGrath wrote a short article Higgs boson: the particle of faith for The Telegraph newspaper. It is worth reading carefully and thinking about. Note the article was written before the recent experimental "discovery" of the Higgs boson.
Here is a key part:

The reason why the Higgs boson is taken so seriously in science is not because its existence has been proved, but because it makes so much sense of observations that its existence seems assured. In other words, its power to explain is seen as an indicator of its truth. 

There’s an obvious and important parallel with the way religious believers think about God. While some demand proof that God exists, most see this as unrealistic. Believers argue that the existence of God gives the best framework for making sense of the world.

Unfortunately, McGrath's point is subtle and was lost on many of the Telegraph readers who wrote comments on the article. Indeed, at first I did not like the article. However, on reflection I decided it is worthwhile because it raises some important questions.

The point is that the practice of science involves faith, i.e. acting on the belief that certain things are (or may be) true or certain entities exist. This is not identical to the faith I practice as a Christian, but it is still faith. Elementary particle physicists had significant reasons to believe that the Higgs boson existed. This faith motivated spending a lot of government money and their careers designing and conducting experiments to find more direct evidence that the Higgs boson existed. Yet, even before the recent experimental results most believed it existed, even though they had never "seen" it.
But, to the hard core "logical positivist" or "skeptic" surely this faith is "irrational".
In particular, why orient your daily life and professional career around something you have never seen. A valid counter is that these physicists were not assuming that the particle existed, but rather trying to see whether or not it did exist. Not finding it would have been just as worthwhile an outcome.